Lonworks Technology: Architecture, Protocol, and Applications

This article covers Lonworks basics and the Lontalk protocol. Lonworks is used in IoT (Internet of Things). We’ll also explore Lonworks devices, including the Lonworks gateway.

Lonworks, short for local operating network, is a powerline communication technology used for home and building automation. Developed by Echelon, it’s an open standard available to all manufacturers. Lonworks has moved away from centralized automation control systems towards a highly distributed, peer-to-peer architecture.

Instead of a central controller, all Lonworks devices (nodes) communicate with each other using a standard protocol over various mediums. Lonworks supports physical mediums such as twisted pair, power line, RF, fiber optics, infrared, and coax. The data rates and distances achievable within a Lonworks system depend on the medium used. Each node has its own application program, distributing control logic throughout the Lonworks system.

Lonworks technology relies on these key elements:

• Neuron chip control processor: This System on a Chip (SoC) device includes multiple processors, RAM, ROM, and interface ports. The ROM stores the operating system, Lontalk communication protocol, and I/O library. The RAM holds configuration data and the application program, which are downloaded to it via the network. Each Neuron chip has a unique 48-bit Neuron ID.
• Transceiver: This acts as the interface between the neuron chip and the physical medium (channel).
• Lontalk Communication Protocol: This layered, packet-based, serial, peer-to-peer communication protocol is media-independent. It is designed for the requirements of control systems and not data processing systems.
• Lonworks network services: A client-server architecture is used to provide interoperability between Lonworks network tools. The software design will enable tools to install, maintain, monitor and control the networks.

Understanding the Lontalk Protocol Process

• Devices transmit packets on a channel in turn. The packet size varies and contains application layer information, addressing, and other network-related information. There are two packet types: those containing application layer packets and those containing network management packets.
• Every device receives the packet and checks the address to see if it’s intended for it. If so, it decodes the packet and takes action based on its type. Network management packets are processed accordingly, while application layer packets are passed to the relevant application program. An ACK message is sent if required.

Lonworks System Components

A Lonworks system consists of three primary components:

• Lonworks devices (nodes): These contain a neuron chip and transceiver, along with a power supply. They can function as sensors or actuators, depending on their functionality. Each device has a unique Neuron ID.
• Channels: These are the physical mediums used by groups of Lonworks devices. The devices use transceivers to communicate over the channel.
• Network tools: These are software programs that reside in the neuron chip or on a PC. They are used for network installation, configuration, monitoring, maintenance, and supervisory control.

Lonworks Specifications

Figure depicting a Lonworks system mentioning a Lonworks gateway that interfaces with Modbus and Lonworks protocol devices.

The Lonworks protocol stack consists of the physical layer, link layer, network layer, transport layer, session layer, presentation layer, and application layer.

Lonworks Gateway Manufacturers

Here are some manufacturers of Lonworks gateways, which essentially act as protocol converters:

• Sierra Monitor Corporation
• Control Solutions, Inc. Minnesota, USA
• LG Electronics
• Efficient Building Automation Corporation, CANADA
• Renu electronics Pvt. Ltd, Pune INDIA
• DAIKIN INDUSTRIES, LTD, JAPAN

Chipkin Automation Systems has developed Lonworks gateways for various protocol conversions, including:

• Lonworks to BACnet converter
• Lonworks to Modbus
• Lonworks to KNX
• Lonworks to SNMP
• Lonworks to HTTP